/**
 * Copyright (c) 2006-2015, JGraph Ltd
 * Copyright (c) 2006-2015, Gaudenz Alder
 */
mxCodecRegistry.register(function () {
  /**
	 * Class: mxModelCodec
	 *
	 * Codec for <mxGraphModel>s. This class is created and registered
	 * dynamically at load time and used implicitely via <mxCodec>
	 * and the <mxCodecRegistry>.
	 */
  var codec = new mxObjectCodec(new mxGraphModel())

  /**
	 * Function: encodeObject
	 *
	 * Encodes the given <mxGraphModel> by writing a (flat) XML sequence of
	 * cell nodes as produced by the <mxCellCodec>. The sequence is
	 * wrapped-up in a node with the name root.
	 */
  codec.encodeObject = function (enc, obj, node) {
    var rootNode = enc.document.createElement('root')
    enc.encodeCell(obj.getRoot(), rootNode)
    node.appendChild(rootNode)
  }

  /**
	 * Function: decodeChild
	 *
	 * Overrides decode child to handle special child nodes.
	 */
  codec.decodeChild = function (dec, child, obj) {
    if (child.nodeName == 'root') {
      this.decodeRoot(dec, child, obj)
    } else {
      mxObjectCodec.prototype.decodeChild.apply(this, arguments)
    }
  }

  /**
	 * Function: decodeRoot
	 *
	 * Reads the cells into the graph model. All cells
	 * are children of the root element in the node.
	 */
  codec.decodeRoot = function (dec, root, model) {
    var rootCell = null
    var tmp = root.firstChild

    while (tmp != null) {
      var cell = dec.decodeCell(tmp)

      if (cell != null && cell.getParent() == null) {
        rootCell = cell
      }

      tmp = tmp.nextSibling
    }

    // Sets the root on the model if one has been decoded
    if (rootCell != null) {
      model.setRoot(rootCell)
    }
  }

  // Returns the codec into the registry
  return codec
}())
